develooper Front page | perl.perl5.porters | Postings from August 2010

Re: RFC: New regex modifier flags; also the whimsical nature of backward compatibility; new 'r' flag has issues

Thread Previous | Thread Next
From:
David Golden
Date:
August 6, 2010 13:52
Subject:
Re: RFC: New regex modifier flags; also the whimsical nature of backward compatibility; new 'r' flag has issues
Message ID:
AANLkTikNT7K7Uc5ObbOeC4yVby7hxPze3YkKsXOi09rq@mail.gmail.com
On Fri, Aug 6, 2010 at 4:28 PM, karl williamson <public@khwilliamson.com> wrote:
> Your statement above was making a lot of sense to me, wondering if my
> muddled thinking was a result of lack of sleep, or Alzheimer's.  But what I
> hadn't been clear about to you guys, is that it isn't as bad as this.  The
> parser would do look-ahead to rule out things like unless and until.  They
> can't be regex modifiers because they have an 'n' in them.

You might just be too close to the problem at this point.  :-)

By the way, I wasn't saying that it's not possible to resolve the
ambiguity by looking ahead -- I was only identifying the leading
characters that cause us to have *any* conflict whatsoever.

> Off the top of my head, subject to further reflection, I don't have a
> problem with this.  Why your analysis doesn't pick up 'gt' remains a
> concern, are you or I wrong here?

A "g" in a list of regex modifiers would be consumed and there are no
operators or statement modifiers beginning with t.  So a trailing "gt"
is a syntax error now and adding "t" to the list of modifiers doesn't
"break" anything.

> And should the d be D for consistency?

It could be.  I don't have strong feelings about it.  I expect it to
be used rarely.  I figured we should use lower case unless we have
conflicts requiring upper case.  If you want to do all three upper
case, I'll leave that to you as the patch writer.  :-)

> And, I'm starting to learn this new-fangled IRC stuff.

screen and irssi were the big discoveries for me a few years ago
(thanks, rjbs!).  Without them, I wouldn't be able to keep up or use
it effectively.

-- David

Thread Previous | Thread Next


nntp.perl.org: Perl Programming lists via nntp and http.
Comments to Ask Bjørn Hansen at ask@perl.org | Group listing | About